Improvement in automatic hot and gold air dampers



2 sheets -sheet L J. w. ORARY] Automatic Hot and Cold Air Damper.

' Patented Dec. 9,1879.

N. Firm, PHOTO-LITHOGRAPHER, WASHING 2 Bhe. ets-Sheet 2,

J. W. 'GRARY.

Automatic Hot and Cold Air Damper.

-No. 222,387. Patented Dec. 9, 1879.-

TIGJB m /re flwefimy. WAZW M 4 I MV%WW IMPEIERS, PHDTO-UTNOGRAPHER, WASHINGTONv D C.

- each other.

.UNIT D STATES {PATENT OFFICE.

JoHN w. GRARY, or PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN AUTOMATIC HOT AND. COLD AIR DAMP E-RS.

' Specification forming part of Letters Patent No. 222,387, dated December 9, 1879; application "filed May 27, 1878.

v The object of my invention isa simple, cheap,

and durable automatic damper that will check the'draft of a furnace by admitting cold-air pressure at the same time the smoke-flue is partly closed; and the invention consists in the combination of a cold-air damper and hotair damper on the same rod with a cold-air box and smoke-flue, the cold-air box having a flue which has an open communication with the smoke-flue, which may be located any desirable distance therefrom, all. as hereinafter fully described.

I am aware that it is not new to operate two dampers simultaneously by means of the same rod, so as to close one while the other is being opened, as this is shownin the patent of Hessenburch, dated January 19, 1869, and in that of Tingley, dated September 28, 1875. In the patent of Hessenburch the dampers a and I) in the pipes A and B, respectively, are on separate rods, which have no connection with A connection of the dampers is made by a rod pivoted at one end to one end of the damper b, and at the other'end to the damper a, in such a manner that the opening of one damper causes the other to close, and

vice versa. Tin gley has two dampers upon the same rod but the rod is in the center of each damper, so that neither damper is automatically moved-by the pressure of the air upon it; but my damper is essentially difierent from Tin gleys, and also from that of Hessenburchs, the cold-air damper being connected at one of its edges with the damper-rod, so that the pressure of the air upon it automatically moves it, and consequently the smoke-damper, as hereinafter fully described.

' In the accompanying drawings, which make a a part of this specification, Figure 1 is an isometrical view of my automatic damper. Fig.

2 is a like view of the dampers F and G, dam per-rod E, and indicator H, detached from the cold-air box A and smoke-flue 0. Fig. 3

is a horizontal viewat the broken .line of Fig. 1.

Like'letters of reference inall thefigures indicate the same parts.

A is the cold-air box, which, in the "drawings, is shownin a vertical position,'and"B a cold-air flue connected at oneendtherewith, to be inserted in a wall or pipe wherever they are intended to be used. 0 is the smoke-flue, which, in practice, is made separate from the flue B, so as to be located any desirable distance from the cold-air box A. D is a dialon 1 the outer end of the cold-air box A. E is the damper-rod, one end of which has a. bearing in the center of the dial D and the end of the box A, to which the dial is attached, The otherend has its bearing in the far side of the smoke-flue G. Fis the cold-air damper in the cold-air boxA, and G the smoke-damper in the smoke-flue 0, both dampers being on the same rod E. They are in the same plane; but the openings to be opened and closed are at right angles to each other. Hence one is closed by one of the dampers, while the other is opened -by the other damper. The cold-air damper F is attached at one edge to the rod 'E, so as to be automatically moved by the pressure of the. air. a

It will be readily understood that, as the coldair box A has an open communication by means of its connecting-flue B with the smokeflue O, the temperature of the air within the the difl'erence of pressure, cause the valve to open, and thus partly close the smoke-damper, and that a reverse action will be produced by a diminution of the temperature of the air in the smoke-flue 0.

Outside of the dial D on the projecting end of the rod E is the hand or indicator H, which is adjustable on the rod by any suitable means,

so as to balance the cold-air damper F to give I sensitiveness to its movements, and thus to insure its being easiiy moved by cold-air pressare.

Either metal or clay is a suitable material for the cold-air box and fines or for the dampers. The simultaneous action of the dampers admits of a certain pressure against the outflowing products of combustion in the fine 0 at the same time the flue is partly closed by the damper G. This is desirable, because this damper is never sufliciently closed to prevent the escape, of noxious gases, while the entering cold air cools the smoke-flue only above the damper, and the gas is thus carried off without any unnecessary loss of heat from the furnace.

The cold-air box A, and also the smoke-flue 0, may be set eitherin a. horizontal or vertical position, as may be desired.

I claim as my invention--- 1. The c0ld air box A, having an ingressopeuing for the passage of cold air and a coldair flue, B, in combination with the smoke'iiue C, the cold-air box being placed at any dc.

sirable distance from the smoke-flue, and having an open communication therewith by means of the flue B, and the air-box and smoke-flue being provided with suitable automatic dampers, substantially in the manner and for the purpose set forth.

2. The combination of the coldair damper F, smoke-damper G, and rod E, the damper F being adapted to automatically open and close the mouth of the cold-air box A, and thereby regulate the draft of the smoke-flue G, substantially as set forth.

3. The combination of the dampers F and G, rod E, cold-air box A, having aflue, B, and the smoke-flue G, the several parts being constructed and combined in relation to each. other substantially in the manner and for the purpose set forth.

JOHN W. GRARY.

Witnesses:

THOMAS J. BEWLEY, STEPHEN UsTIoK. 

